Thank you Matthew. To be more accurate, my question is about the expected
r-values indicating an existing connectivity between brainstem ROI to the
cortical areas. I have not seen many articles reporting the values of the
significant correlation coefficients and so I am wondering why it is not
considered to be important.

In my case, I have found significant connectivity from the specific
brainstem ROIs, but looking at the peak significant r-values, they are not
exceeding 0.05. From the mathematical point of view, such a small r-value
means the two compared variables are irrelevant; at the same time, it is
not possible to ignore that the cortical pattern of these significant
mathematical irrelevance seem to be meaningful. I believe that I am missing
a point, where your expert opinion might help me to figure out.

Thanks a lot,
Amin


On Mon, Jul 9, 2018 at 10:48 PM, Glasser, Matthew <[email protected]>
wrote:

> There is more unstructured noise in HCP data because of small voxel size
> and fast TR.  Basically that means the ratio between the neural signal and
> the random noise is lower and that leads to lower correlation coefficients.
>
>
> Peace,
>
> Matt.
>
> From: <[email protected]> on behalf of Amin Dadashi <
> [email protected]>
> Date: Monday, July 9, 2018 at 4:14 AM
> To: hcp-users <[email protected]>
> Subject: [HCP-Users] Brainstem to cortex baseline r-value
>
> Dear HCP users,
>
> Recently, I have tried to calculate the zero-order correlation between
> some brainstem ROIs and the cortical vertices. Looking at the mean
> subjects' correlation map, the connectivity pattern totally makes sense.
> Even after doing the statistical testing (using permutation based on
> maximum t-statistics) the significant correlated clusters are located in
> the expected areas. However, the magnitude of the correlation coefficients
> are very small (in the order of 0.05 for the peak vertices in the mean
> map). I have also done the volume-based voxel-wise analysis for the same
> brainstem ROIs and I had similar findings there.
> Is there any explanation for such small r-values even though the
> significant correlations seem to be meaningful?
>
> Thank you all,
> Amin
>
> _______________________________________________
> HCP-Users mailing list
> [email protected]
> http://lists.humanconnectome.org/mailman/listinfo/hcp-users
>
>
> ------------------------------
>
> The materials in this message are private and may contain Protected
> Healthcare Information or other information of a sensitive nature. If you
> are not the intended recipient, be advised that any unauthorized use,
> disclosure, copying or the taking of any action in reliance on the contents
> of this information is strictly prohibited. If you have received this email
> in error, please immediately notify the sender via telephone or return mail.
>

_______________________________________________
HCP-Users mailing list
[email protected]
http://lists.humanconnectome.org/mailman/listinfo/hcp-users

Reply via email to